More than 600 robo-geeks flexed their mental muscles Saturday in the second annual Rock River Off-Season Competition for robotics.

Five area teams hosted the event at the Rock Valley College Physical Education Center: The Metalheads from Freeport, Winnovation from Winnebago, Rockford Robotics (public, private and home schools), the Flaming Monkeys from Belvidere and Stateline Robotics from Rockton.

Rockford Robotics captain Addie Longberry, a junior at Keith Country Day School, said the competition has grown substantially in the past year. Last year had 21 teams entered; this year, 32 teams from Illinois, Wisconsin, Michigan, Indiana and Missouri are on the roster.

The conference champions: Roboteers of Tremone, Winnovation, Ctrl-Z of Champaign and Flaming Monkeys 2. Click here for the day’s coverage.